Re: [PATCH] blk-core: use pr_warn_ratelimited() in bio_check_ro()

[yebin (H)]

On 2023/11/7 19:12, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@xxxxxxxxxx>
>
> If one of the underlying disks of raid or dm is set to read-only, then
> each io will generate new log, which will cause message storm. This
> environment is indeed problematic, however we can't make sure our
> naive custormer won't do this, hence use pr_warn_ratelimited() to
> prevent message storm in this case.
>
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> ---
>   block/blk-core.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 9d51e9894ece..fdf25b8d6e78 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -501,8 +501,8 @@ static inline void bio_check_ro(struct bio *bio)
>   	if (op_is_write(bio_op(bio)) && bdev_read_only(bio->bi_bdev)) {
>   		if (op_is_flush(bio->bi_opf) && !bio_sectors(bio))
>   			return;
> -		pr_warn("Trying to write to read-only block-device %pg\n",
> -			bio->bi_bdev);
> +		pr_warn_ratelimited("Trying to write to read-only block-device %pg\n",
> +				    bio->bi_bdev);
Acctually, before commit  57e95e4670d1 ("block: fix and cleanup 
bio_check_ro") , there's only print warning once.
I wrote a patch earlier, set GD_ROWR_WARNED flag for disk after emit 
warning. You can look at the patch in the
attachment, Is it possible to solve your problem.
>   		/* Older lvm-tools actually trigger this */
>   	}
>   }